题目选项分析

比较两个句子语法结构语义，选出最佳答案：

The army cutworm moth is a critical source of fat for as many as a third of Yellowstone National Park's grizzly bears, which overturn rocks to find the insects, consuming as many as 40,000 per bear in a single day.

The army cutworm moth is a critical source of fat for as many as a third of Yellowstone National Park's grizzly bears, and they overturn rocks to find them and consume up to 40,000 per bear in a single day.